It is known to use a coupled cavity together with a cavity containing a gain medium, the coupled cavity being used for the purpose of outcoupling the laser beam and for controlling the laser. Copending application Ser. No. 348,566, assigned to the Assignee of this application, illustrates a laser in which a coupled cavity includes a modulator within the cavity which is used to Q-switch and cavity dump the laser beam. Frequency control of the laser beam is accomplished by using a grating to form one end of the coupled cavity.